a) Keeps on increasing with moisture content
b) Increases to a certain point and then decreases
c) Keeps on decreasing with moisture content
d) Decreases to a certain point and then increases

Answer: b
Explanation: The volume i.e. bulking increases as sand absorbs moisture. At about 6- 10%, the film starts breaking and the volume reduces. If sand absorbs further moisture, no bulking takes place.